Step 1 - Understanding the structure of the molecule
IF5 is a covalent molecule, whose electronic structure is shown below:
Each F atom has 3 remaining electron pairs, which are omitted in the drawing above.
Step 2 - Predicting its geometry
According to VSERP theory, when we have five atoms bonded to a central atom, and there's also an electron pair in the central atom, the geometry is a square piramid:
Answer: square pyramidal
